Dimming device.



0.. R. JFQRD.

DIMMING DEVICE. APPLICATION FILED MAY4. 1918.

1,297,822. Patented Mar. 18,1919.

' wrmsssss mvsu'ron I the invention consists in the novel features OTIS RAYMOND FORD, OF PITTSBURGH, PENNSYLVANIA.

DIMMING DEVICE.

Specification of Letters Patent.

Patented Mar. 18, 1919.

Application filed May 4, 1918. Serial N 0. 232,522.

To all whom it may concern:

Be it known that I, O'rrs RAYMOND FORD,.

a citizen of the United States, and a resi dent of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Dimming Devices; and I do hereby declare the following to be a full, clear, and exact description thereof.

This invention relates to dimming devices for automobile headlights, and is particularly adapted for use in a circuit having an alternating or a direct current from 'a generator.

The principal object of this invention is to provide a dimming device that will be small and neat in appearance and may be readily attached to a steering post or other convenient portion of an automobile, and in which the resistance causing thedimming action on the lights may. be readily increased or decreased according to the will of the operator.

A further and important object is to provide a device of this class embodying a rotary contact member traveling over or along a resistance member in such a manner as to eliminate or reduce to a minimum the wear upon such last named member.

lVith the above and other objects in view,

of construction, combination and arrangement of parts hereinafter fully described and claimed, and illustrated in the accompanying drawings, in which- Figure 1 is a longitudinal sectional view of my device; 7

Fig. 2 is a vertical longitudinal sectional view thereof;

Fig. 3 is a detail view of the resistance coil; and

Fig. 4 is a diagrammatic view of a circuit embodying my invention.

Referring more particularly to the drawings, the numeral 2 designates the casing of my device preferably composed of the portion A which comprises the top and sides, and the portion B which comprises the base and ends.

A coil member 3 is adapted to be mounted within the casing 2. Such coil member comprises a core 4: having asbestos or other heat insulating material 5 secured therearound, and a resistance wire or material 6 wrapped around and 'over the asbestos material 5. The whole of the coil is adapted to be covered by a cement or other insulating inclosing material 7 which is of such a. character that it will impregnate the asbestos 5 and firmly engage around and hold the unins'ulating wires 6 in position. The material 7i is cleaned or cut away forming a. narrow path along the top face of the coil member 3 to provide an exposed surface of the resistancewires 6, which may be engaged by a contact member (to be described).

The coil member 3 has its non-conductive core Projecting at each end' and has screw threaded standards 8 passing therethrough at each end. The standards 8 and standards 9 are adapted. to hold or support a suitable plate 10 having its central portion cut away formingin reality a rectangular frame. The standards 8 and 9 are screwthreaded into the plate or frame 10. With the standards 8 passing through and not engaging with the plate 10 a-sufficient distance above the plate 10 to permit of their.

threaded engagement with the to of the portion A of the casing 2. It wil thus be seen that the coil 3 and plate 10 are held firmly together, and the coil is held in engagement with the casing by the standards 8 while the plate is held in engagement by he standards 9.

The one end 'of the resistance Wire forming the coil 3 is adapted to be secured to the binding post 12 and the plate 10 is adapted to have a'lead wire 13 secured to the opposite binding post 14. The binding post 14L is adapted to have the positive feed wire from the generator secured thereto, and the opposite binding post 12 is adapted to have a lead wire leading therefrom to the lights.

A suitable contact member C is mounted to slide upon the plate 10 and is in engagement with the coil 3 to complete the circuit from the contact member 14 through coil 3 to the front binding post 12. Such contact member comprises a cross plate or support? ing plate 15 having slotted ends 16 slidably nrounted on the plate 10, and a suitable post has extending out therefrom a handle or 110 grip portion 22 for moving said post along the coil 3. v

It will be understood thatthe ball-shaped member 20 of the contact member is adapted to travel in the longitudinal path 7 formed on the coil by cutting away the covering substance 7 or in other Words, on the exposed surface of the resistance Wire 6, and since the circuit through the coil 3 is made through such contact, that the amount of resistance may be increased or decreased according to the position of such contact memmember.

. Referring particularly to Fig. 4, which shows a circuit, the generator is indicated by the numeral 23 and the negative wire of such generator is grounded, as is the ordinary custom in automobile circuits, to any suitable portion of the machine. The positive wire 24: from the generator 23 is led to the binding post 14:, which is in circuit with the plate 10. The circuit from the plate 10 follows through the contact member C to the coil 8, .thence through the binding post 12 to the wire 25, to the lights 26, the lights 26 having their negative wire 27 therefrom grounded to complete the circuit.

The operation of the device is as follows: The dimmer being secured to the steering post or other convenient portion of the automobile and connected, as shown in the diagram of circuit in Fig. 4c, the switch for the lights being turned on to complete the circuit, the contact member C is moved along the coil 3 until the lights reach their desired brilliance or dullness, Whichever may be desired. As the contact member C is moved along the coil 8, the ball member 20 will rotate in the recess 18 so as to roll over the different convolutions of the resistance wires 6, thus preventing any cutting r the wires 6 due to the tension of the spring member 19.

The contact member C is normally held firmly against the plate member 10 due to the pressure of the spring 19, and thus will not jolt or fall from its desired position, and when it is desired to move such contact member, it will be necessary to apply a slight downward pressure upon the grip portion 22 in order to lessen the pressure against the plate 10.

While I have shown and described the invention as applied to an automobile circuit, it will be expressly understood that it may be used in many other circuits wherever a resistance is desired.

Having thus fully described my invention, what I claim is: I

1. A device of the class described comprising a casing, a coil within said casing, a metallic plate secured in the upper-portion of said casing, a contact including a crossplate slidably mounted on said plate and in engagement with said coil, said contact comprising a handy grip portion extending out through a slot in said casing, and a spring pressed member mounted in said grip portion and engaging said coil.

2. A device of the class described comprising a casing, a coil within said casing, a metallic open frame plate secured in the upper portion of said casing, a contact including a plate for engaging with said coil extending across the open portion of said .frame plate and being sli'dably mounted on said frame-plate by means of slotted ends,

said contact having a hand grip portion extending out through a slot in said casing, and a spring pressed member mounted in said grip portion and engaging said coil.

In testimony whereof, I, the said OTIS RAYMOND Form, have hereunto set my hand.

OTIS RAYMOND FORD.

Witnesses:

J. M. GEOGHEGAN, JOHN E. JAoKsoN. 

